Flight Controls Flashcards
What is the only primary flight control that is not FBW?
Aileron
What is the main difference between the ailerons and the other flight controls?
The ailerons are driven by conventional control cables that are connected to hydraulic actuators (hydro-mechanical) while the rest of the flight controls are FBW. FBW hydraulic actuators are called power control units (PCU)
You are looking at the flap position on the EICAS and position indicator is showing amber. What does this mean?
The flaps are in transit. It will turn green when stable
What will the EICAS display if a flap jam occurs?
EICAS message plus an amber box on the flap display
What are the two basic flight control modes of operation? If all systems are operating normally what will be the flight control mode?
Normal and Direct, normal
What is the difference between the normal and direct modes of operation?
- There are no higher functions available in direct
- The FCMs are removed
How does the Fly by wire system work?
The FCM units are connected to the ACE via the controller area network bus (CAN BUS) providing digital inputs to the ACE that are combined with pilot inputs
What are the primary control electronics?
Primary - Actuator control electronics (P-ACE)
- Flight control module (FCM)
How many ACE’s are installed? How many channels does each one have?
9 (3 P-ACE, 2 SF-ACE, 3 Spoiler ACE, and 1 HS-ACE)
- 2
Explain in general terms what the direct mode is?
The flight control mode (FCM) is removed form the control loop and the control limits default to the values set by the primary actuator control electronics (P-ACE). The highest level functions of the particular flight control are removed.
There are three Flight Control Mode guarded buttons. What do they do?
When pushed in the put the associated flight system into the direct mode from the normal mode bypassing the FCM and all higher level functions
What three flight systems have Flight Control Mode buttons?
Rudder, Spoilers, Elevator
What would cause the FCM to go into the direct mode?
The loss of airspeed data
Can the direct mode be selected by the pilot?
Yes, but pressing the FLT Control Mode button on (out is normal)
Will the multi-function spoilers function in the DIRECT mode? Will speed brakes/ground spoilers?
Multi-function spoilers - Yes, but a default fixed gain is used
Speed brakes/ground spoilers - No, they’re controlled by the FCM
Is AOA Limit Protection available in direct mode?
No
Can you stall the airplane in direct mode?
Yes
The stall protection system provides warning to the pilot when the aircraft speed is approaching stall speed. How does it do this?
The AFCS activates the stick shaker on the control column
How does the FCM provide stall protection?
By means of the AOA limiting function
What does the AOA limiting function do?
Reduces control column authority in the nose up direction gradually reducing until the control column reaches the aft stop thereby limiting AOA
FCM computes an AOA limting command using what?
AOA data, control column position and inertial feeback
A pitch limit indicator shows what? Why speeds correlate to what color? (Amber and red are the same for the low speed awareness tape)
- Shows margin between AOA and stick shaker activation
- Green: 1.2 Vstall to 1.13 Vstall
- Amber: 1.13 Vstall to Vshaker
- Red: at or below Vshaker
What three surfaces are shown on the Flight Control System Status Annunciation?
Rudder, Elev LH, Elev RH
Which elevator surface does HYD Sys 1 control? HYD System 2? HYD System 3?
Left outboard - System 1
L and R inboard - System 2
Right outboard - System 3
Which HYD System is not used for the rudder?
System 2
Which hydraulic system power the inboard aileron PCUs? Outboard aileron PCUs?
HYD system 2
HYD system 3
Which HYD systems power which rudder surface? Which HYD system is not used for the rudder?
- HYD system 1 powers upper rudder
- HYD system 3 powers lower rudder
- HYD system 2 is not used
Which HYD systems power the ground spoilers?
- HYD system 1 powers L2 and R2 (outboards)
- HYD system 2 powers L1 and R1 (inboards)
There is an upper and lower rudder surface. What about the elevators?
There is an inboard and outboard elevator surface
If a jam occurs in one elevator what happens to the system?
That one surface remains fixed and the pilot controls the remaining elevator surfaces
How can a pilot disconnect a jammed rudder?
He can’t
Where can you find a visual representation of the flight control system operations and parameters?
The flight control system synoptic on the MFD
What are the higher level functions associated with pitch
Gain on airspeed, elevator thrust compensation, AOA limiting
Going from Normal to Direct mode how is the ridder affected?
You’ll lose the higher level functions
What is the elevator thrust compensator function?
- It moves the elevator +- 5 deg to compensate for engine thrust changes
- Stabilizes the aircraft about the pitch axis and will only be available in normal mode only, as computed by the FCM
What are the higher level functions associated with yaw (rudder)?
- Yaw damp
- Turn coordination
- Thrust asymmetry
- Gain on airspeed
What do you lose when you into Direct mode
All the higher level functions for the associated flight control
Where would the stab trim setting be displayed on the flight deck
In the lower right corner of the EICAS display
Do we have a trim check procedure?
Yes. Verify roll, yaw and pitch (main and backup) trims are operating properly in both directions. Verify systems’ 3-second protection is working properly. Adjust yaw and roll trim to the neutral position and pith trim to the green band
What is the purpose of the pitch trim switch?
To trim the airplane when the autopilot is off
What is the green takeoff band of the pitch trim?
-1 to -6 degrees
The HS-ACE responds to?
Trim commands from the backup trim, captain trim, FO trim and FCM trim inputs
What is the priority for the trim system?
- Backup
- Captain
- FO
- Autopilot (FCM, auto-trim)
Does the trim switch activate the trim through the FCM?
No, only the autopilot trim uses the FCM
If only 1/2 of a trim switch is erroneously actuated for more than 7 seconds what happens?
That switch will automatically be deactivated, an aural warning “trim” will be activated for 6 seconds and advisory EICAS message will be displayed requiring maintenance to clear
How would we trim the stabilizer if the normal trim doesn’t function?
Use the backup pitch trim switch on the center console
What will happen if using the backup pitch trim switch?
Autopilot will disengage
How are the light controls trimmed?
Roll and yaw: Ailerons and rudder surface repositioned to new neutral position
Pitch: horizontal stabilizer
What does pressing the AP/TRUM DISC button do?
Disconnects both HS-ACE channels but only while held. Releasing it will activate the channel again
What prevents aileron runaway trim
There is a 3-second timer that limits trim activation to no more than 3 seconds
What happens if the yaw or roll trim switches are held in position for more than 3 seconds
The trim stops. The switch must now be released and re-energized to the next application
Can we disable channel 1 or 2 of the HS-ACE?
Yes, by using the pitch trim Sys 1 (2) guarded button on the center console trim panel. The respective channel is disabled when pushed in (out is normal)
Which flight controls use electrical power instead of hydraulic power for actuation?
Flaps, slats, horizontal stabilizer
How does the aileron control system work?
Commands are transferred mechanically to two hydro-mechanical actuators through cables
If the flap/slat lever is left between positions 2 and 3 as an example, what do the flaps/slats do?
They remain at the last selected position
On the E-170 which takeoff flap settings are approved?
1, 2 and 4
Why is flap/slat position 4 have a gated stop?
For normal go around and takeoff
What two flap lever positions provide identical flap and slat positions
Flaps 4 and 5
How many degrees of flap and sea does full flaps provide?
35 degrees flap and 25 degrees slat
If the flap/slat lever is out of the 0 position, how will invalid slat information be shown on the EICAS display?
The slat will be removed from the display
What are the two main parts of the fly by wire primary flight control electronics?
Primary Actuator Control Electronics (P-ACE) and Flight Control Modules (FCM)
What do the Flight Control Modules do?
They provide software based airspeed gain schedules and control limits to the P-ACE as well as high level functions
How is roll controlled?
Ailerons and multi-function spoilers (outer 3 spoilers on each wing)
If the rudder trim is held in the left or right position for longer than 3 seconds, the rudder trim does what?
The trim stops. The knob must now be released and re-engaged for further trim
How many multi-function spoilers are on each wing? What are their functions? Which spoiler panels function as ground spoilers?
- 3 outboard spoilers are used to assist in roll control and for ground spoilers
- Ground spoiler function commands all 10 ground spoilers at the full rate
When does full multi0function spoiler extension occur>
- Weight on wheels on ground
- Wheel speed is above 45 knots or airspeed is above 60 KIAS and
- Thrust Lever Angle (TLA) is below 60 degrees
Do all multi-function spoiler panels deploy symmetrically in response to speed brake lever position?
Yes
Can a FCM override pilot input?
No, pilot always has supreme control
When will the speed brakes automatically close even if the lever shows deployed?
Flaps >= 2, Airspeed > 180 knots, or TLA > 60 deg
What is the flap/slat extension/retraction sequence?
Slats extend first, flaps retract first
How do the artificial feel units operate?
Preloaded springs
What happens to the artificial feel if flight controls are disconnected?
Artificial feel is felt at 1/2 the normal load
Does the feel system still work in the event of a jammed control wheel resulting in separation?
Yes, each torque tube has it’s own spring but the feel will be lighter (1/2 of normal load)
If the captain’s and FO’s control column is separated can they reconnect them?
No, can only be manually reset by maint
In the event of an aileron jam followed by a disconnect which side has normal feel and which side has no feel?
Captain’s side has normal feel, FO side has no feel
After a disconnect, the pilot of he non jammed side retains control over which elevator?
The onside elevator
There are inner, middle and outboard spoilers on each wing. In the event of a disconnect due to jamming which side controls which spoilers
- Captain side controls outboard
- FO controls middle
- Inboard spoilers are disabled
If the aircraft has touched down and the ground spoilers have deployed. When the thrust levers are advanced beyond 60 deg TLA, the spoilers do what following rollout?
Automatically retract
What happens to the flight control system when the RAT is the only AC power source?
- Horizontal stab trim operates at 1/2 speed
- Slat/flap system operates at 1/2 speed
- Slat/flap position is limited to ‘3’ to allow adequate airspeed for the RAT
What hydraulic pump is being used when the RAT is deployed?
Hydraulic pump 3A
What happens when the STALL WARNING SHAKER CUTOUT (1) or (2) button is pushed?
Cuts out the associated shaker channel
How would you be alerted to an AOA limit failure?
An EICAS message
What happens when the stick shaker is activated?
Control column authority is limited in the nose up direction
Do you have to arm the spoilers prior to landing?
No, the FCMs will automatically deploy the spoilers as part of the landing roll
The two aileron PCUs per side operate the aileron surface:
in active/standby configuration
In case of a single electric motor failure within the flap PDU, how will the system operate?
The flap/slat system will operate at a low rate speed
When do the flaps/slats work only at 1/2 speed?
RAT deployment
Design maneuvering speed?
240 knots
As you reach VMO the multifunction spoilers will do what and why?
Extend at 8 deg to prevent overspeed
Max flap extension altitude? Why?
20,000ft, mach tuck
In case of aileron, rudder or elevator fail what is the max airspeed?
220 KIAS
What are the 2 flap limitations?
- Enroute use is prohibited
- Do not hold in icing with flaps extended
What indication on the EICAS would indicate the speed brakes are open?
A white SPDBRK annunciation
What are the 5 thrust reverser limitations
Ground use only, full stop landings only, do not attempt go around, power back prohibited, idle reverse below 60 knots
What is the memory item for JAMMED CONTROL COLUMN (PITCH)? JAMMED CONTROL WHEEL (ROLL)?
- ELEVATOR DISCONNECT handle - PULL (PITCH)
- AILERON DISCONNECT handle - PULL (ROLL)
When does the horizontal stabilizer trim function work at a low speed?
- RAT deployment (electrical emergency also)
- Loss of airspeed data from the FCM
